Sleep is arguably one of the most important and most underrated parts of our day to day lives. In fact, it is just as important for health as good nutrition and exercise. Adequate sleep is associated with improvements in concentration, focus, athletic performance, weight management, immune function, and mental wellbeing.
Despite the wonderful benefits of sleep, it is often the first thing to drop on our list of priorities. But I will also be the first to admit a noticeable difference in my health and wellbeing when I am getting sufficient sleep.
Interestingly, research shows that sleep disturbance is very common among individuals with IBS. This includes difficulty falling asleep, frequently waking up, shorter sleep duration, and non-restorative sleep. Additionally, sleep disorders are estimated to impact up to 55% of IBS patients.
But why is poor sleep quality particularly concerning for IBS sufferers? Well, there is a relationship between disturbed sleep and exacerbation of gastrointestinal (GI) symptoms. So inadequate and or poor-quality sleep often equates to a worsening of IBS symptoms.
Why does sleep impact IBS symptoms?
Rest and digest – or lack thereof
Our autonomic nervous system (ANS) contributes to both GI function and sleep. The ANS is regulated by two key sub-systems – the parasympathetic nervous system (PNS) and the sympathetic nervous system (SNS).
The PNS controls the balance and repair of our bodies when at rest (i.e. asleep), also known as the ‘rest-and-digest’ response. So a poor night's sleep = less time for your body to rest and digest. As a result, this can exacerbate IBS symptoms.
In contrast, the SNS kicks in during times of stress – known as the ‘fight-or-flight’ response. This pauses non-vital functions, such as digestion and sleep. Inadequate sleep generally means a reduced capacity to deal with stress, and the SNS can then takes over. This causes a disruption to digestion and may accelerate GI transit time, which can exacerbate IBS symptoms.
Poor sleep and inadequate sleep also cause disruptions to several chemicals important in gut-brain signalling and GI function.
As mentioned above, inadequate/poor sleep disrupts gut-brain signalling and chemical balance. Whilst the exact mechanism responsible for sleep disorders in IBS patients remains unclear, this ANS disturbance resulting in chemical/metabolite disruption is one proposed mechanism. Research shows the following chemical changes related to sleep disturbance are common in IBS patients:
- Increase in cortisol levels
- Cortisol is a stress hormone, which is released as part of the fight-or-flight response. High cortisol levels have been shown to exacerbate IBS symptoms, particularly for IBS-D (diarrhoea predominant)
- Reduction in the serotonin/melatonin pathway. The highest concentrations of Melatonin and Serotonin are found in the gut. Research shows reductions in Serotonin and Melatonin are common in sleep disorder patients, and IBS patients.
Serotonin and melatonin are both key regulators of the sleep-wake cycle and have important roles in GI function. In fact, some research shows melatonin supplements may improve IBS symptoms in some patients (mainly constipation-predominant IBS patients), due to the effect of modulating colonic activity. This suggests potential promise for the use of melatonin as a future treatment for IBS management.
Ways to work on sleep
Sleep is something that should be a priority for everyone, regardless of whether you have IBS. Here are a few handy tips on ways to improve your sleep quality/duration:
- Aim for a minimum of 7-8 hours of sleep per night
- Avoid the use of technology 1-2 hours before bed. The blue light from screens can impair melatonin production, and therefore impact sleep.
- Avoid eating 2-3 hours before bed. Try not to have a large meal before bed and avoid eating high FODMAP foods which may cause an overnight flareup.
- Try limiting caffeine intake to before lunchtime
- Avoid exercising <2-3 hours before bed.
- Consider taking a magnesium supplement 30 minutes before bed. Research shows magnesium may help with sleep.
- If concerned with sleep, consult your GP for further investigation.
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Reviewed by the healthylife Advisory Board March 2022